I drive a '91 DX sedan and have had a '91 LX sedan and '91 DX hatch, all with 5spd. My DX sedan has 323k on it and I have done nothing to the engine other than regular maintenance and replacing the distributor. My lifetime average FE is around 42 mpg in mostly highway driving, approaching 50 mpg in the summer using pulse-and-glide. The car is all stock except for VX wheels and narrower tires.
Enjoy your new old car!